Mr Brunson, 50, an evangelical Christian pastor originally from North Carolina, was let out of jail on Wednesday after 18 months to serve house arrest because of “health problems”, according to Turkey’s official Anadolu news agency.

President Donald Trump has repeatedly demanded Mr Brunson’s release and said on Twitter last week that the pastor’s detention was “a total disgrace”.

“Brunson is an innocent man, there is no credible evidence against him,” Mr Pence said.

If convicted, Mr Brunson faces up to 15 years in prison for “committing crimes on behalf of terror groups without being a member”, references to outlawed Kurdish militants and the network of a US-based Muslim cleric blamed for a failed coup attempt. He could receive another 20 years if he is found guilty of espionage.

Mr Brunson strongly denies the charges.

Turkish President Recep Tayyip Erdogan has previously linked Mr Brunson’s return to the US to the extradition of Fethullah Gulen, the cleric Turkey’s government holds responsible for the failed July 2016 military coup.

Mr Gulen, who denies orchestrating the coup attempt, lives in Pennsylvania. Turkish requests for his arrest and extradition have not been granted.

At the end of a recent hearing, the court inside a prison complex in western Turkey rejected Mr Brunson’s lawyer’s request that he be freed pending the outcome of the trial. The case was adjourned until October 12.